enum还有人记得吗？

enum其实挺好用的，特别是对于一些固定的东西！

package com.pki.test;

import sun.security.pkcs11.wrapper.CK_MECHANISM;

enum KeyAlg {
	// 枚举常量放在第一行
	SM2("SM3withSM2"), RSA("SHA1withRSA");

	public final int keySize;
	public final String signName;
	public final CK_MECHANISM mechanism;
	public final CK_MECHANISM signMechanism;
	public final boolean isSM2;

	// 枚举的构造必须是私有的
	private KeyAlg(String signName) {
		this.signName = signName;
		if (name().equals("SM2")) {
			keySize = 256;
			mechanism = new CK_MECHANISM(0x80008201L);
			signMechanism = new CK_MECHANISM(0x80008101L);
			isSM2 = true;
		} else {
			keySize = 1024;
			mechanism = new CK_MECHANISM(0x80008201L);
			signMechanism = new CK_MECHANISM(0x1L);
			isSM2 = false;
		}
	}

	// 空构造是默认的
	private KeyAlg() {
		keySize = -1;
		signName = null;
		mechanism = null;
		signMechanism = null;
		isSM2 = false;
	}
}

public class EnumTest {
	static KeyAlg keyAlg = KeyAlg.RSA;

	public static void main(String[] args) {
		// 枚举常量的名
		System.out.println(keyAlg.name());
		// 该常量在枚举中的位置
		System.out.println(keyAlg.ordinal());
		// 通过name得到枚举常量
		System.out.println(KeyAlg.valueOf("SM2").name());
	}
}